The proposed USC/Norris Comprehensive Cancer Center Microarray Core Facility is located at Children Hospital Los Angeles, the pediatric facility of the Center. It consists of a well equipped, 500 sq. ft. molecular biology laboratory with newly installed Affymetrix confocal laser scanner, a fluidics work station for hybridization and washing of samples applied to Affymetrix Gene Chips, a hybridization oven, and a high-speed Windows NT work station that both controls all functions of the and provides initial analyses of chip data. This equipment was purchased with funds awarded this past year from NCI to the Children's Cancer Group, specifically to Dr. Triche. It is intended in part for analysis of cooperate group pediatric cancer cases. The additional capacity (at least 50% funding of the current personnel on this grant, commensurate with projected use by Center members. In addition, we propose a 50% position for Dr. Paul Marjarom, a mathematician trained in computational biology to work both independently and with biostatisticians in the Department of Preventive Medicine at USC to provide-state-of-the-art analyses of gene expression and single nucleotide polymorphism (SNP) data generated by this core. With such support, Cancer Center investigators will be able to submit, or have submitted from the Translational Pathology Core Facility, cells or tissue of interest for a given project. Services available will include gene expression profiling with a variety of arrays, including human, mouse, and rat; mutation analyses (p53); HIV, yeast, and bacterial genome analyses; and SNP analyses. Samples will be received by Ms. Liu at the CHLA core. RNA or DNA will be extracted, purified, labeled, and in the case of expression chips, converted to double stranded cDNA, arrays specified by the investigator, scan them, and determine the quality of hybridization. The data will then be interpreted by Dr. Marjoram, the computational biologist, who will confirm the findings with the director and pass these results to the investigator on a CD. Additional analyses will be available on a matching computer workstation at Norris Cancer Center. Array and supplies cost will be charged back to the investigator.